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Emergency Medicine > CARDIOVASCULAR
Patent Ductus Arteriosus
Article Last Updated: Apr 14, 2008
AUTHOR AND EDITOR INFORMATION
Section 1 of 11  
Author: Girish Sethuraman, MD, MPH, Clinical Assistant Instructor, Staff Physician, Department of Emergency Medicine, Kings County Hospital, Downstate Medical Center
Girish Sethuraman is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American Medical Association, American Public Health Association, and Society for Academic Emergency Medicine
Coauthor(s):
Christopher I Doty, MD, FAAEM, Assistant Professor of Emergency Medicine, Residency Program Director, Department of Emergency Medicine, Kings County Hospital Center, State University of New York Downstate Medical Center
Editors: Mark S Slabinski, MD, FACEP, FAAEM, Vice President, EMP Medical Group; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Gary Setnik, MD, Chair, Department of Emergency Medicine, Mount Auburn Hospital; Assistant Professor, Division of Emergency Medicine, Harvard Medical School; John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center; Charles V Pollack, Jr, MD, MA, FACEP, Professor, Department of Emergency Medicine, University of Pennsylvania College of Medicine; Chairman, Department of Emergency Medicine, Pennsylvania Hospital
Author and Editor Disclosure
Synonyms and related keywords:
PDA, patent ductus arteriosus, ductal closure, bacterial endocarditis, late congestive heart failure, CHF, development of pulmonary vascular obstructive disease, circulatory abnormalities, ventilatory abnormalities, congenital heart diseases
Background
Patent ductus arteriosus (PDA) is the persistence of a normal fetal structure between the left pulmonary artery and the descending aorta. Persistence of this fetal structure beyond 10 days of life is considered abnormal.
For a related CME/CE activity, see CME/CE - A Newborn Presenting in Extremis.
Pathophysiology
The ductus is derived from the 6th aortic arch. From the 6th week of fetal life onwards, the ductus is responsible for most of the right ventricular outflow. It contributes to 60% of the total cardiac output throughout the fetal life. Only about 5-10% of its outflow passes through the lungs. The ductus arteriosus is an important structure in fetal development as it contributes to the flow of blood to the rest of the fetal organs and structure. Closure of the ductus before birth may lead to right heart failure. At birth, the ductus normally undergoes closure. A PDA is variable in its presentation. It may be vary in size from small to large and may not be picked up based on physical exam at birth. The available retrospective data on the natural history of untreated patent ductus arteriosus are poor; however, complications can arise. Spontaneous ductal closure can occur without treatment.
Complications of untreated PDA include bacterial endocarditis, late congestive heart failure (CHF), and the development of pulmonary vascular obstructive disease. PDA can complicate other circulatory or ventilatory abnormalities.
Frequency
United States
PDA is the fifth or sixth most common congenital cardiac defect. It often is associated with other intracardiac structural defects. PDA represents 5-10% of all congenital heart diseases, excluding those in premature infants. It occurs in approximately 8 of 1000 live premature births. In term infants, the incidence is about 1 in 2000 births. The female-to-male ratio is 2:1.
Mortality/Morbidity
- Morbidity and mortality rates are directly related to the flow volume through the ductus arteriosus.
- A large patent ductus arteriosus may cause CHF; if left untreated for a long period, development of pulmonary vascular obstructive disease may occur. Occasionally, the ductus arteriosus patency can be intermittent.
- It is estimated that left untreated, the mortality rate is 20% by age 20 years, 42% by age 45 years, and 60% mortality rate by age 60 years. An estimated 0.6% per year undergo spontaneous closure.
Race
No data support a race predilection.
Sex
Females are 2-3 times more likely than males to develop PDA.
Age
Patent ductus arteriosus is a common problem in premature infants and is less likely to be noted as gestational age increases to full term. Incidence ranges from 20% in premature infants older than 32 weeks' gestation up to 60% in those younger than 28 weeks' gestation.
Up to 30% of low birth weight infants (<2500 g) develop a patent ductus arteriosus.
Occasionally, an older child is referred with the late discovery of a typical ductus arteriosus murmur (eg, machinery or continuous murmur).
History
The history is variable depending on the size of the lesion and the coincident left-to-right shunting of blood through the pulmonary circulation.
- When the ductus arteriosus is small, no symptoms are present.
- A ductus arteriosus with a moderate-to-large left-to-right shunt may be associated with a hoarse cry, cough, lower respiratory tract infections, atelectasis, or pneumonia.
- When the defect is large, CHF with dyspnea and poor weight gain or failure to thrive are the main presentations.
Physical
- Tachypnea
- Tachycardia
- Diaphoresis
- Cyanosis
- Bounding peripheral pulses and wide pulse pressure
- Hyperactive precordium
- Systolic thrill
- Occasionally, with increased pulmonary artery pressure, accentuation of the pulmonic component of the second heart sound is heard.
- A grade 1-4 of 6 continuous or machinery murmur is best heard at the upper left sternal border or left infraclavicular area.
- An apical diastolic rumble with a large left to right shunt may be present.
- Occasionally, auscultation of the PDA reveals numerous clicks or noises resembling shaking dice or a bag of rocks.
- The murmur may be only a systolic ejection murmur, or it may be a crescendo/decrescendo systolic murmur that extends into diastole.
- Clubbing
Causes
- Prematurity
- Low birth weight
- Prostaglandins
- Maternal rubella in the first trimester of pregnancy is thought to be a cause of the seasonal incidence of PDA.
- High altitude and low atmospheric oxygen tension have been associated with persistence of the PDA.
- Hypoxia
Anemia, Acute
Anemia, Sickle Cell
Aortic Regurgitation
Cardiomyopathy, Dilated
Mitral Regurgitation
Pediatrics, Bacteremia and Sepsis
Pediatrics, Respiratory Distress Syndrome
Pediatrics, Tachycardia
Pericarditis and Cardiac Tamponade
Pulmonic Valvular Stenosis
Shock, Cardiogenic
Tetralogy of Fallot
Other Problems to be Considered
Cervical venous hum (usually present on the right side of the neck and more prominent in the sitting position, varying with respiration)
Coronary artery fistula
Ruptured sinus of Valsalva
Tetralogy of Fallot with pulmonary atresia and collateral circulation
Coarctation of the aorta
Pulmonary arteriovenous fistula
Systemic arteriovenous fistula (cerebrovascular or hepatic arteriovenous malformations)
Ventricular septal defect (VSD) with aortic regurgitation
Absence of the pulmonary valve
Tetralogy of Fallot with absent pulmonary valve
Persistent truncus arteriosus
Aortopulmonary septal defect
Peripheral pulmonary artery stenosis
Total anomalous pulmonary venous return
Lab Studies
- Pulse oximetry/arterial blood gas analysis
- Usually demonstrates normal saturation because of pulmonary overcirculation
- A large ductus arteriosus could cause hypercarbia and hypoxemia from CHF and air space disease (atelectasis or intra-alveolar fluid/pulmonary edema).
- In the event of persistent pulmonary artery hypertension (persistent fetal circulation); right-to-left intracardiac shunting of blood, diminished pulmonary blood flow with resultant hypoxemia, cyanosis, and acidemia may be present.
Imaging Studies
- Chest radiography
- Findings range from normal to consistent with CHF
- Cardiomegaly with or without CHF
- Prominence of the main pulmonary artery segment is an early sign of increased pulmonary artery pressure and flow.
- Echocardiography/Doppler imaging - Procedure of choice to confirm a diagnosis of PDA
- Contrast echocardiography
- Cardiac catheterization
- Computed tomography
- Magnetic resonance imaging (MRI)
Other Tests
- Electrocardiography
- Results are usually normal in infants or those with smaller ductal shunts.
- Sinus tachycardia or atrial fibrillation may be present in moderate-to-large shunts.
- It may also reveal left ventricular and left atrial hypertrophy in children and adults or in those with larger shunts.
- Further progression of disease is dependent on volume and pressure relationships.
- Volume = pressure/resistance
- High volume yields increasing pulmonary artery pressures eventually producing endothelial and muscular changes in the vessel wall.
- These changes may eventually lead to pulmonary vascular obstructive disease (PVOD), a condition of resistance to pulmonary blood flow that may be irreversible and will preclude definitive repair.
Procedures
- Cardiac catheterization and angiography is not indicated for the uncomplicated PDA. It may be used as a therapeutic procedure for coil embolization.
- Demonstrates the shunt
- Determines the amount of shunt
- Determines pulmonary pressure
- Determines other coexisting cardiac abnormalities
Prehospital Care
Prehospital care for a suspected PDA consists of supplemental oxygen for any hypoxia and supportive care.
Emergency Department Care
- General measures
- Pulmonary support
- Oxygen to correct hypoxemia
- Sodium and fluid restriction
- Correction of anemia
- Medical management consists of amelioration of CHF symptoms.
- No exercise restriction is required in the absence of pulmonary hypertension.
- Prophylaxis against infective endocarditis is recommended.
Consultations
Pediatric surgery
- Indications for surgical treatment include the following: failure of indomethacin treatment, contraindications to medical therapy (eg, thrombocytopenia, renal insufficiency), signs and symptoms of CHF, and PDA found in an older infant. Infants found to have an asymptomatic PDA after the neonatal period should undergo surgical ligation preferably before the age of 1 year to prevent future complications of a PDA.
- Ductal closure is indicated for cardiovascular compromise (ie, pulmonary complications) and for reduction of the risk of infective endocarditis (subacute bacterial endocarditis).
- Contraindications to surgery include pulmonary vascular obstructive disease.
- Ligation (with or without division of the PDA) without cardiopulmonary bypass can be performed through a left posterolateral thoracotomy.
- Video-assisted thoracoscopic surgery (VATS) ligation of PDA is less invasive than the posterolateral thoracotomy. It has been shown to be safe and effective.
- Timing of surgery is at 1-2 years or whenever the diagnosis is made in an older infant.
- In infants with CHF, failure to thrive, pulmonary hypertension, or recurrent pneumonia, the operation is more urgent (ie, within 3-6 months).
Pediatric cardiology
- Transcatheter occlusion has been performed in the cardiac catheterization laboratory and is an effective alternative to surgical intervention and is increasingly becoming the treatment of choice for most PDAs in children and adults. This involves coil embolization or the use of an occluder device.
Medication use in PDA is based upon the clinical status of the patient. Prostaglandins are utilized to maintain the patency of the ductus arteriosus until surgical ligation is performed.
When surgical ligation is not indicated, prostaglandin inhibitors (eg, NSAIDs) are used to close the ductus arteriosus.
Indomethacin is currently the drug of choice for closure of the ductus in premature infants.
Other studies have shown equal effectiveness with ibuprofen. The dose used for ibuprofen is 10 mg/kg bolus followed by 5 mg/kg/d for 2 additional days. Ibuprofen was initially thought to have less adverse effects such as decreased incidence of oliguria, gastrointestinal toxicity, and cerebral hypoperfusion. The use of ibuprofen has been shown to increase the incidence of pulmonary hypertension and chronic lung disease. Intravenous ibuprofen is currently not available in the United States. A Cochrane Database of Systematic Reviews article has showed no statistically significant difference in closure between ibuprofen and indomethacin.1 A decision to use one drug versus another should be based upon the infant's presentation and comorbidities.
A similar Cochrane Database of Systematic Reviews article looking at initial treatment of symptomatic PDA in preterm infants showed no difference in risks or benefits of surgery versus the use of cyclooxygenase inhibitors.2
Drug Category: Prostaglandin
Promote vasodilatation by direct effect on the vasculature and smooth muscle of the ductus arteriosus.
| Drug Name | Alprostadil (Prostin VR Pediatric) |
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| Description | Used to maintain patency of the ductus arteriosus when a cyanotic lesion or interrupted aortic arch presents in a newborn. PGE1 is most effective in premature infants. |
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| Pediatric Dose | Initial infusion: 0.05-0.1 mcg/kg/min IV
Maintenance infusion: 0.01-0.4 mcg/kg/min IV; titrate to lowest effective dose
Usual maintenance dose is 0.1 mcg/kg/min IV but is often possible to reduce the dosage by 50-90% |
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| Contraindications | Documented hypersensitivity; respiratory distress syndrome; persistent fetal circulation |
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| Interactions | None reported |
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| Pregnancy | X - Contraindicated; benefit does not outweigh risk
|
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| Precautions | Adverse effects and toxicity include apnea, seizures, fever, hypotension, pulmonary overcirculation, and inhibition of platelet aggregation; because of the potential risk of apnea with the use of PGE1, neonates usually are intubated prophylactically; use cautiously in neonates with bleeding tendencies; prolonged use occasionally is necessary (in hypoplastic left heart syndrome transplant candidates) and may be associated with third spacing of fluid |
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Drug Category: Nonsteroidal anti-inflammatory agents (NSAIDs)
These agents inhibit the production of prostaglandins by decreasing the activity of cyclo-oxygenase. The result is a functional closure of the PDA in 80% of patients.
| Drug Name | Indomethacin (Indocin) |
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| Description | Promotes closure of the PDA. Onset of action is generally within min. |
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| Pediatric Dose | 0.2 mg/kg IV, then 0.1 mg/kg q12h IV for 2 doses
Alternative dosing:
<7 days: 0.2 mg/kg IV, then 0.1 mg/kg IV at 12 and 36 h after initial dose
>7 days: 0.2 mg/kg IV, then 0.2 mg/kg IV at 12 and 36 h after initial dose |
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| Contraindications | Documented hypersensitivity; GI bleeding; renal insufficiency |
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| Interactions | Coadministration with aspirin increases risk of inducing serious NSAID-related adverse effects; probenecid may increase concentrations and, possibly, toxicity of NSAIDs; may decrease effect of hydralazine, captopril, and beta-blockers; may decrease diuretic effects of furosemide and thiazides; monitor PT closely (instruct patients to watch for signs of bleeding); may increase risk of methotrexate toxicity; phenytoin levels may be increased when administered concurrently |
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| Pregnancy | B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus
|
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| Precautions | Acute renal insufficiency, hyperkalemia, hyponatremia, interstitial nephritis, and renal papillary necrosis may occur; increases risk of acute renal failure in patients with preexisting renal disease or compromised renal perfusion; reversible leukopenia may occur, (discontinue if leukopenia, granulocytopenia, or thrombocytopenia persists) |
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Further Inpatient Care
- Small PDAs in full-term infants may spontaneously close without intervention. Large PDAs are unlikely to close.
- Patients who present with CHF need medical therapy for CHF followed by a definitive procedure to close the PDA by either surgery or catheterization.
- Surgical repair is recommended for patients with small-to-large PDA because of the risk for endocarditis. Complications of surgical ligation are mostly related to the left lateral thoracotomy. Surgical morbidity and mortality rates are negligible, and early postoperative complications are associated with other complications of prematurity.
Further Outpatient Care
- Prophylaxis for infective endocarditis (subacute bacterial endocarditis [SBE]) should be followed at times of predictable risk (bacteremia) until the patient can undergo repair. (Specific recommendations for prophylactic antibiotics can be found in any current infectious disease or antibiotic reference.)
Transfer
- Transfer to a tertiary care center is mandatory for a patient in extremis presenting in florid CHF once stabilized with diuretics and positive pressure ventilation, as indicated.
Complications
- PGE1 should be used to maintain patency of the ductus arteriosus once it is established that a ductal dependent lesion exists. However, PGE is a pulmonary vasodilator and could cause exacerbation of CHF by means of increasing pulmonary blood flow.
- Left heart failure
- Pulmonary hypertension
- Right heart hypertrophy and failure
- Eisenmenger physiology
- Bacterial endocarditis
- Myocardial ischemia
- Necrotizing enterocolitis
Prognosis
- An excellent prognosis is expected for uncomplicated PDA.
- Severity of the symptoms and associated cardiac anomalies modify the outcome.
- Spontaneous closure in those older than 3 months is rare.
- In those younger than 3 months, spontaneous closure in premature infants is 75%.
- Postoperative results are best if closed while the patient is younger than 3 years.
- An increased incidence of elevated pulmonary vascular resistance and pulmonary hypertension occurs if closed in those older than 3 years.
- No firm statistics exist, but survival rates are decreased in patients with large shunts.
Patient Education
- Parents should be aware that this lesion does not have any significant inheritance pattern.
Medical/Legal Pitfalls
- Treating CHF as an upper respiratory infection (URI) (failure to diagnose PDA)
- Identification of additional cardiac malformations, such as coarctation or interrupted aortic arch or pulmonary atresia, is the most important requirement prior to pharmacological or surgical closure of the PDA.
- A ductal dependent lesion, as outlined above, requires the persistence of a PDA to ensure adequate pulmonary blood flow.
- Failure to administer prophylactic antibiotics for medical procedures with a bacteremia risk
| Media file 1:
Patent ductus arteriosus. Schematic diagram of left-to-right shunt of blood flow from descending aorta via patent ductus arteriosus (PDA) to main pulmonary artery |
 |  View Full Size Image | |
Media type: Image
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- Ohlsson A, Walia R, Shah S. Ibuprofen for the treatment of patent ductus arteriosus in preterm and/or low birth weight infants. Cochrane Database Syst Rev. Jan 23 2008;CD003481. [Medline].
- Malviya M, Ohlsson A, Shah S. Surgical versus medical treatment with cyclooxygenase inhibitors for symptomatic patent ductus arteriosus in preterm infants. Cochrane Database Syst Rev. 2008;(1):CD003951. [Medline].
- Benders MJ, van de Bor M, van Bel F. Doppler sonographic study of the effect of indomethacin on cardiac and pulmonary hemodynamics of the preterm infant. Eur J Ultrasound. May 1999;9(2):107-16. [Medline].
- Bensky AS, Raines KH, Hines MH. Late follow-up after thoracoscopic ductal ligation. Am J Cardiol. Aug 1 2000;86(3):360-1. [Medline].
- Brook MM, Heymann MA. Patent ductus arteriosus. In: Heart Disease in Infants, Children and Adolescents. Vol I Section III, Part A. 1995:746-64/chap 54.
- Burke RP, Jacobs JP, Cheng W, et al. Video-assisted thoracoscopic surgery for patent ductus arteriosus in low birth weight neonates and infants. Pediatrics. Aug 1999;104(2 Pt 1):227-30. [Medline].
- Castaneda AR, Jonas RA, Meyer JE. Surgery for infants with congenital heart disease. In: Kirklin JW, Barrett-Boyes BG, eds. Cardiac Surgery. 1993:841-61.
- Fyler DC. Patent ductus arteriosus. In: Nadas Pediatric Cardiology. 1992:525-34.
- McConnell ME, Adkins SB 3rd, Hannon DW. Heart murmurs in pediatric patients: when do you refer?. Am Fam Physician. Aug 1999;60(2):558-65. [Medline].
- Park MK. Specific congenital heart defects: patent ductus arteriosus. In: Pediatric Cardiology for Practitioners. 1988:134-7.
- Schneider DJ, Moore JW. Patent ductus arteriosus. Circulation. Oct 24 2006;114(17):1873-82. [Medline].
- Silverman NH. Patent ductus arteriosus. In: Pediatric Echocardiography. 1993:167-77.
- Snider AR, Serwer GA. Abnormal vascular connections and structures: patent ductus arteriosus. In: Echocardiography in Pediatric Heart Disease. 1990:264-71. [Medline].
- Wyllie J. Treatment of patent ductus arteriosus. Semin Neonatol. Dec 2003;8(6):425-32. [Medline].
Patent Ductus Arteriosus excerpt Article Last Updated: Apr 14, 2008
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